I think, it is not just using the M mode, but using it correctly. Cuz using the m mode, it is much easier to set the camera to take the pictures to your intent. I mean, some like it darker, some like to expose for the highlights. But using the M mode, is not the end all of taking a picture. One needs to understand the camera, and then overcome the camera limitations. Usually I use M mode with center weight metering, takes some of the guesswork out.
I train myself with a manual 85mm F1.8 lensand play arouund with aperture and shutter speeds
Pentaxian for Life
K1, K3, DA*16-50, Sigma 70-200, FA31, 43 & FA77 Limiteds, DA18-135WR, DA50-200WR
I started off using M.
To find out that I need to spend some time adjusting the right settings and sometimes missing a shot.
These days, use AV for walk about (scenery, landscape etc..)
I still use M for some specific shots that I have in mind.
i am of the opinion that there is a time and place for all the settings on a camera. it's simply about becoming conversant to the point in which they become an aid and not a limitation.